Metaprogramming, defined as creating application programs by writing programs that produce programs, is presented as the basis of a method for reducing software costs and improving software quality. The method starts with a rapid prototyping phase in which selected representative parts of the application are prototyped, followed by a “tooling up” phase, during which the metaprogramming occurs. The final phase is the production of the application programs using the software tools and techniques of the metaprogramming phase. We summarize the experience of two projects that support the as-sertation that metaprogramming is an efficient way to produce programs, since these projects used metaprogramming in their development. We also present the outlines of an economic theory which justifies this approach, and shows how to do a cost/benefit analysis of the method.